简介：Amultipurposecloneplantspecies,Hippophaerhamniodeshasthecapacityforindefinitelongevity,althoughundersuccessivedroughtstressitmayoftendeclineordieacrosslargeareas.Fieldtrialswereconductedover2yearstoexaminetheeffectsofvariedirrigationintensitiesonmodulargrowthandclonalpropagationinasemi-aridarea.Irrigationlevelsincludedacontrol,aswellastwo,fourandsixtimesthevolumeofwaterthatwastypicallyreceivedvialocalannualaverageprecipitation.Irrigationintensitysignificantlyinfluencedclonalpropagationcapacity(numberofdaughterramets),abovegroundmodulargrowth(height,basediameter,andcrownwidth),belowgroundmodulargrowthincludedrootnoduledryweight,stretchingcapacityoflateralroots(lengthofthelongestlateralroots,anddiameteroffirstgradelateralroots),andbranchingintensityoflateralroots(numberoflateralrootsbifurcationgrade,numberoffirstgradelateralroots).Themodulargrowthandthedensityofdaughterrametsweresmallundernon-irrigationorlowirrigation,andbecamelargerwithincreasedirrigationintensity.Beyondacertainthreshold,however,furtherincreasesinirrigationintensityresultedinareversiontothedevelopment.Theoptimalirrigationintensitiesforgrowthandpropagationwere3.48–5.29timesthevolumeofnominallocalannualaverageprecipitation.Therewereeffectsofirrigationintensitiesonthepositivesignificantcorrelationsbetweenabovegroundandbelowgroundmodulargrowths,andonclonalpropagationcapacities.Undervariouswatertreatments,H.rhamnoidesmayadapttotheenvironmentthroughtheregulationofgrowthandpropagation.WeconcludedthatwatershortagesacttoweakenthegrowthandpropagationofH.rhamniodesplantations.

简介：Background:Wooddensityisconsideredtobethemostimportantpredictorofwoodqualitybutdespiteitsimportance,diffuse-poroustreespecieshavebeenthesubjectofonlyalimitednumberofstudies.TheimportanceofEuropeanbeechforestsforCentralEuropecallsforprofoundresearchtoexaminethepotentialimpactofawarmerclimateonthequalityofbeechtimber.Methods:Inthisstudyweanalysedtheinfluenceoftree-ringwidthandtree-ringageonthewooddensityofbeech,andwhetherthewooddensityresponsetothesetwoparametersismodifiedbyaspect.Alinearmixed-effectsmodelforwooddensitywasconstructedformeandensitydatameasuredwithhighfrequencydensitometryonstemdiscsfrom72beechtreessampledfromtwodifferentaspects(northeast-NEandsouthwest-SW)ofavalleyinsouthwesternGermany.Results:Partofthevariabilityofmeanannualwooddensitywasexplainedbycambialage:anincreaseincambialageresultedinanincreaseinmeanwooddensity.Tree-ringwidthandaspecthadonlyasmallinfluenceonwooddensity.WooddensityontheSWaspectwaslowerthanontheNEwithadifferenceofapproximately0.006g/cm3.Thebetween-treevariabilitywasveryhigh.Conclusions:Thesignificantinteractionbetweencambialageandaspectreflectstheimportanceofsiteconditionsatoldertreeages:withincreasingcambialagethedifferencebetweenaspectsbecomesstronger.Ourresultsgiveabetterunderstandingoftheimportanceofsiteconditionsonthewoodqualityofbeech.

简介：Background:Inrecentdecades,nativeAraucariaforestsinBrazilhavebecomefragmentedduetotheconversionofforesttoagriculturallandsandcommercialtreeplantations.Consequently,theforestdynamicsinthisforesttypehavebeenpoorlyinvestigated,asmostfragmentsarepoorlystructuredintermsoftreesizeanddiversity.Methods:Wedevelopedadistance-independentindividualtree-growthmodeltosimulatetheforestdynamicsinanativeAraucariaforestlocatedpredominantlyinsouthernBrazil.Thedatawerederivedfrom25contiguousplots(1ha)establishedinaprotectedarealeftundisturbedforthepast70years.Theplotsweremeasuredat3-yearintervalsfromtheirestablishmentin2002.Alltreesabovea10-cmdiameteratbreastheightweretagged,identifiedastospecies,andmeasured.Becausethisforesttypecompriseshundredsoftreespecies,weclusteredthemintosixecologicalgroups:understory,subcanopy,uppercanopyshade-tolerant,uppercanopylight-demanding,pioneer,andemergent.Thediameterincrement,survival,andrecruitmentsub-modelswerefittedforeachspeciesgroup,andparameterswereimplementedinasimulationsoftwaretoprojecttheforestdynamics.Thegrowthmodelwasvalidatedusingindependentdatacollectedfromanotherresearchareaofthesameforesttype.Tosimulatetheforestdynamics,weprojectedthespeciesgroupandstandbasalareasfor50yearsunderthreedifferentstand-densityconditions:low,average,andhigh.Results:Emergentspeciestendedtogrowinbasalarea,irrespectiveoftheforestdensityconditions.Conversely,shade-tolerantspeciestendedtodeclineovertheyears.Underlow-densityconditions,themodelshowedagrowthtendencyforthestandbasalarea,whileunderaverage-densityconditions,forestgrowthtendedtostabilizewithin30years.Underhigh-densityconditions,themodelindicatedadeclineinthestandbasalareafromtheonsetofthesimulation,suggestingthatundertheseconditions,theforesthasalreadyreachedit

简介：Background:InmidhillsofWesternHimalayas,HimachalPradeshIndia,growth,yieldandeconomicsofSolanumkhasianumasapotentialmedicinalherbunderPinusroxburghii(Chirpine)plantationhasbeenstudiedfortwoconsecutiveyearstoassesstheperformanceofSolanumkhasianuminundercanopyofPinusroxburghiifordevelopingSolanumkhasianumandPinusroxburghiibasedinnovativesilvi-medicinalsystem.Methods:Growthparameterssuchasplantheight,numberofbranchesperplantandleafareaindexfollowedbyyieldwereestimatedafterSolanumkhasianumwasgrownonthreetopographicalaspectsas;Northern,North-westernandWesternataspacingof45cmx45cm,followedbythreetillagedepthsas;minimum(0cm),medium(upto10cm)anddeeptillage(upto15cm),inopenandbelowcanopyconditionstreatment.ThestudywasconductedtoexplorethepossibilityofusingSolanumkhasianumbasedsilvi-medicinalsystemtoutilizethebelowcanopyofChirpineforestforenhancingtheproductivityofforestsbesidestheconservationofthemedicinalherb.Results:Thegrowthparameterssuchasplantheight,numberofbranchesperplantandleafareaindexwerenonsignificantlyaffectedbytopographicalaspectsandtillagepractices,bothbelowcanopyandopenconditionsexceptfreshweightanddryweightofberriesduringharvestingstage.Themaximumyield(0.61t·ha~(-1))wasobservedonWesternaspectinopenconditionsascomparedtobelowcanopyofChirpine.ThehighestgrossreturnswereobservedforthecropcultivatedonWesternaspectunderdeeptillageinopenconditionsthanotheraspectandtillagecombinations.HoweverthepositivenetreturnsfromthecropsraisedinbelowcanopyofChirpineindicatesitspossibleeconomicviabilityunderagroforestrysystemasthegrossreturnswashigherthanthecostofcultivation.Conclusion:SolanumkhasianumwhengrowninbelowcanopyofPinusroxburghii,itsgrowthandyieldindicatedpositivenetreturns.SolanumkhasianumandPinusroxburghiibasedsilvi-medicinalsystemha

简介：Treegrowthtraits(treeheight,DBHandstemvolume)andsurvivalfromtwo9-year-old,open-pollinatedprogenytestsofChinesefirwereinvestigatedforheritability,genotype9environmentinteraction,age-agegeneticcorrelationandselectionefficiency.The97and79familiesplantedattwositeswerecollectedfromthethirdcycleseedorchard.Individualheritabilitywasestimatedbetween0.05and0.21fortreeheight,DBH,andvolumeandbetween0.45and1.0forsurvival.Fa